1. Field of the Invention
The present invention relates to an image forming technique of the electrophotographic type for a printer, a copier machine, a facsimile machine and the like, and more particularly, to an image forming technique which uses liquid development as a development method.
2. Description of the Related Art
Known as a conventional image forming apparatus utilizing liquid development is a structure in which an electrostatic latent image formed on a photosensitive member (latent image carrier) is developed with a liquid developing agent which is evenly applied in a constant thickness to a surface of a developing agent carrier such as a developer belt and a developer roller and an image without any density variation is formed. As a technique for uniformly applying a liquid developing agent to a surface of a developing agent carrier, the following technique has been proposed. That is, a constant and measured amount of a liquid developing agent is uniformly formed temporarily as a thin film having a constant thickness on a surface of a coating roller and the liquid developing agent uniformly provided on the surface of the coating roller is then applied to a surface of the developing agent carrier, and the surface of the developing agent carrier is evenly coated with the liquid developing agent.
For instance, in the apparatus described in Japanese Unexamined Patent Publication No. H11-153906, a developing agent carrier is formed by a developer belt and a coating roller, and for application of a liquid developing agent to the developing agent carrier, a wire bar is disposed which is obtained by winding a wire around a surface of a metal core (rod-like member). In the case of this wire bar, carrying portions between the wire sections of thus wound wire carry a constant amount of the liquid developing agent. The constant amount of the liquid developing agent carried by the wire bar is supplied to the coating roller from the wire bar as the wire bar and the coating roller rotate while abutting on each other at a predetermined position, and a thin layer of the liquid developing agent having a constant thickness is temporarily formed on a surface of the coating roller. At last, as the thin layer of the liquid developing agent uniformly formed in the constant thickness on the coating roller is applied to the developer belt, the thin layer of the liquid developing agent having the constant thickness is formed on a surface of the developer belt.
Meanwhile, as a structure that the developing agent carrier is formed by a developer roller, such a structure is known in which the coating roller is formed by the wire bar above and the thin layer of the liquid developing agent having the constant thickness is formed on the surface of the developer roller. In other words, as described above, as the wire bar and the developer roller rotate while abutting on each other at the predetermined position, a constant amount of the liquid developing agent carried in the carrying portions of the wire bar is applied directly to the developer roller from the wire bar, and the thin layer of the liquid developing agent having the constant thickness is formed on the surface of the developer roller.